Use of Leukocyte-Depleting Filters During Cardiac Surgery With Cardiopulmonary Bypass: A Review

Abstract

Numerous researchers and clinicians have shown that cardiopulmonary bypass (CPB) plays a large role in the initiation of the systemic inflammatory response during cardiac surgery. The activation of leukocytes during this process has been implicated as one of the major contributors to multi-organ dysfunction experienced by some patients after cardiac surgery. Thus, in an attempt to attenuate the systemic inflammatory response and to reduce the amount of activated leukocytes from the systemic circulation during CPB, leukocyte-depleting filters were developed in the early 1990s. Since the clinical introduction of these filters into the CPB circuit, several articles have been published evaluating the effectiveness of leukocyte filtration; however, the results have been conflicting. This article will review some of the most recent literature, ∼40 papers published within the past 10 years, regarding the use of leukocyte-depleting filters during CPB and its effectiveness in preserving organ function. In addition, the effect of different filtration strategies and the effectiveness of the filter to attenuate the systemic inflammatory response in combination with other mechanical and pharmaceutical strategies will be reviewed.

Is There a Relationship between Pressure Gradients through Contemporary Oxygenators and Immune Cell Proliferation during Cardiopulmonary Bypass? A Pilot Study

“…Cardiac surgery requiring CPB results in the development of a complex systemic inflammatory response (SIR) of varying degrees (7)(8)(9). Tissue damage, contact with foreign surfaces of the CPB circuit, and ischemiareperfusion injury are all involved in the activation of the immune system.…”

“…Once in the damaged tissues, these activated neutrophils release an extensive repertoire of chemokines, cytokines, reactive oxygen species, and proteinases (10). Whereas this immune response is necessary for tissue repair after surgery, the uncontrolled activation of the immune system is associated with exaggerated immune activation and is associated with increased patient morbidity and mortality (7)(8)(9)(10).…”

“…A number of preexisting factors could influence the inflammatory reaction including diabetes and organ function that were not captured. Furthermore, responses to CPB such as hyperlactatemia, hyperglycemia, hemolysis, creatinine, and organ function could also play a role in inflammation independently of the oxygenator (7,9). Such data, if they had been collected would require sophisticated multi-variant analysis which was beyond the capacity of the investigators.…”

“…It is important to understand the distinction between increases in WBC and neutrophils. Whereas some WBC, such as macrophages can play an anti-inflammatory role or post-inflammatory role; neutrophils are neither antiinflammatory nor "pedestrian" and if present in increasing numbers is an accurate indication of an inflammatory state (7,9).…”